Stability control systems have been employed to improve driver safety. Stability control systems may employ differential braking, active or semi-active suspension, active front steering and/or active rear wheel steering to provide the stability control. A stability control system determines the desired vehicle performance by considering steering, braking and acceleration inputs and compares the actual vehicle response with the desired vehicle performance. The vehicle stability control system may include a driver command interpreter (DCI) to determine the desired vehicle behavior.
The stability control system receives vehicle dynamics information from various sensors, such as yaw rate sensors, lateral acceleration sensors, vehicle speed sensors, wheel speed sensors, hand-wheel angle sensors, tire force sensors, wheel force sensors, roll rate sensors, and others to calculate or estimate various vehicle parameters and states. The vehicle parameters and states, as well as target (or desired) states, are used by the stability control system to provide actuator command signals to provide the stability control. The DCI is used to define the target states including the desired yaw rate. Conventional DCIs employ current (and sometimes previous) steering wheel angle, vehicle velocities and accelerations, and a road condition estimate to define the desired states.
For autonomously driven vehicles additional vehicle parameters and states are calculated. Also, in autonomous driven vehicles, steering and acceleration commands are planned in advance (sometimes 10 seconds or even more) of the time that the commands are actually sent to the relevant actuators. The additional vehicle parameters and the future driving instructions that are available in autonomously driven vehicles are not used in conventional stability control systems to compute actuator command signals.
Accordingly, it is desirable to provide a system for using planned steering and velocity information to calculate actuator command signals and allow a vehicle to proactively take an appropriate action ahead of time to prevent the possibility of the vehicle getting into the unstable modes. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and the background of the invention.